impelling vs efficacious

impelling and efficacious both are adjectives.

Word	Noun	Adjective	Verb	Adverb
impelling	No	Yes	No	No
efficacious	No	Yes	No	No

impelling (adjective)	efficacious (adjective)
markedly effective as if by emotional pressure	marked by qualities giving the power to produce an intended effect
	producing or capable of producing an intended result or having a striking effect